The invention relates to a fan, and in particular to a fan rotatable without a motor.
A conventional fan is actuated by a single motor for expelling airflow to dissipate heat from a heat source.
For example, if the different heat sources, e.g. a CPU, a power supply module, an image driver and a case of a computer, are respectively equipped with a conventional fan to dissipate heat, the number of the motors is increased correspondingly and thus noise and cost are increased.